The present invention relates to a developing method and apparatus capable of controlling the progress of development of a predetermined region of a substrate such as a semiconductor wafer during a developing process, to accelerate the development and thereby form a circuit pattern on the substrate so that line widths thereof may be uniform.
In a coating-development system for carrying out a photolithography process during the manufacture of semiconductor devices, for example, a resist coating process is performed in which a resist film is formed on the surface of a semiconductor wafer (hereinafter merely referred to as "wafer") and also a developing process is performed in which the wafer is developed after being applied with the resist and exposed to light.
In the developing process, a wafer, on which light has been irradiated according to a predetermined circuit pattern and which has been subjected to a postexposure-baking process and a cooling process, is transported to a developing unit and mounted to a spin chuck. A developer is supplied from a developer feed nozzle and applied to the entire surface of the wafer to a thickness of, for example, 1 mm. The wafer is then left at rest for a predetermined time with the developer applied thereto, and while the wafer is left to stand, development progresses due to natural convection. The wafer is thereafter rotated by the spin chuck so that the developer may be shaken off, and then a rinsing liquid is discharged from a rinse feed nozzle to wash off the developer remaining on the wafer. Subsequently, the spin chuck is rotated at high speed, whereby the developer and the rinsing liquid remaining on the wafer fly off and the wafer becomes dry. This completes a series of steps of the developing process.
Meanwhile, in recent years, there is an increasing demand for miniaturization of circuit patterns formed on wafers, and to this end, development should desirably be caused to progress so that the line widths of the resulting circuit pattern may be uniform over the entire region of the wafer.
During the development, however, the developer merely remains stationary on the wafer as stated above, and the progress of the development depends entirely upon natural convection of the developer. Further, the line widths of a circuit pattern are affected not only by conditions of the exposure process such as the exposure time and the amount of light exposure, but also by the temperature of the developer, the developing time, etc., and thus it is difficult to cause the development of a circuit pattern to progress in such a manner that the line widths of the resulting circuit pattern are uniform over the entire region of the wafer.